Webinar: Integration of heat, power and intermittent renewables

With the evolution of electricity/power sources and district energy systems (district heating and cooling networks), it is becoming easier - even necessary - to increase the interaction between the two.

Making the most of these synergies is one of the areas where district energy systems have a lot to offer. But with integration comes the need for appropriate business models, as well as technical solutions. From both industry and academia, the experts in this webinar explore the market and technical implications of energy system integration involving heat pumps, thermal storage, thermal grids and renewable electricity sources.

https://www.youtube.com/watch?v=GWUbQjG-Bho&feature=emb_logo 

1. A systemic view of power and District Energy systems

Jens Kühne, Consultant for heat generation and CHP at AGFW
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The concept of Power-to-District-Heat (P2H) is defined, and its application and business models are discussed, with a focus on Germany. P2H can be used in several ways: as balancing power, for use of local/regional surplus electricity from renewable energy sources (RES), or for use of nationwide RES electricity surplus. It is pointed out that the regulatory framework for P2H needs to be adapted.

Questions from the audience:

• Is there a large chance of the change in the framework that you suggest?
• You mentioned two measures for stabilizing the electricity grid. What has the response been to these two?

2. The future of large-scale electric heat pumps in DH systems

Andrei David, Research Assistant at Aalborg University
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The central role of heat pumps in future power production is described. Their role in the 4th generation of DH is discussed. Also, the historic capacity development and possible heat sources are discussed. It is noted that of the possible sources, sewage water has the largest capacity and best future potential. Also, the issues of future refrigerants, output temperatures and coefficients of performance (COPs) are reviewed, as are also heat pump operation modes in different countries. Finally, barriers to the implementation of more large-scale heat pumps are discussed.

Question from the audience:

Is there one single solution (or combination of solutions) that you think would be most useful, or does it depend on the local context?

3. Cost-effectiveness of large-scale heat pumps in district heating networks: a simulation model for a case study in Germany

Eftim Popovski, Research Associate at Fraunhofer ISI
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Focussing on Germany, this presentation deals with the research questions of why there are no heat pumps in DH networks currently, and how to make large-scale HPs competitive. Results that are discussed include the levelized cost of heat (LCOH), sensitivity analysis, electricity price, COP dependence on temperature, and how the cost-effectiveness can be improved. One of the final conclusions is that policies should focus mostly on operational costs, not on capital costs.

Questions from the audience:

• Have you considered a sensitivity analysis with lower investment costs?
• At what COP will the HP be competitive, based on current electricity prices?

4. Interaction between energy systems – the future role of thermal grids

Jay Hennessy, Ph.D. student/researcher at RISE

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The future of thermal grids is discussed, in particular heat-to-power, i.e., producing electricity from heat, using, e.g., the Organic Rankine Cycle (ORC). The economy of this is discussed, including a sensitivity analysis. The biggest constraint for this technology is the temperature of the district heating grid.

Question from the audience:

• Is RISE working on any future applications in terms of the future thermal grids?

5. Thermal energy storage – enables sustainable regions and cities

Håkan EG Andersson, Senior Advisor at Skanska Sverige AB
Magnus Carlström, Busniess Develop,ent Manager at Skanska Sverige AB
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An innovation is described and discussed, based on thermal energy storage (TES). It resembles a large thermos, building on the physical principle of hot water “floating” on cold water. Its advantages are discussed, particularly how they can contribute to sustainable social development.

Questions from the audience:

• Could you tell us a little bit more about how it works?
• What are the most important factors for making the TES cost-competitive?
• Is it feasible on a small scale?

6. General question:

• In existing cities, is it better to renovate buildings and put in individual heat pumps than install a new DH network?

Names of stakeholders

Emilia Pisani, Johanneberg Science Park

External links:

AGFW, Aalborg University, Fraunhofer ISI, RISE, Skanska Sverige AB